II've had a lot of experience converting modules written for other systems to run in Rolemaster, and so didn't expect it to be too hard. And it wasn't. I had to redraw some maps at a 5' square resolution, but that was pretty painless. The 4e MM made converting the monsters very straight forward - lots of minions, and a smattering of goblins of various levels, with 4th level Goblin Underbosses in place of the module's goblin kings. The treasure had to be toned down a bit, but again that was pretty easy. (To give some idea in terms of time - maybe one hour per 5 hour session spent on conversion. I do it on the train on the way to and from work.)Maybe fodder for a different thread, but I'm curious how that worked out. I've converted the other way (run Keep on the Shadowfell in 1e) and while the conversion itself was relatively easy the result wasn't quite what I'd hoped once the dice started flying. I'd be interested in hearing how well a Basic adventure ported to 4e in terms of how well it played.
As to how it played, pretty well. I think that's a feature of the module, however (which is partly why I chose it). The module starts with an assault on the PCs while they're on a boat. It then has a big attack on a fortified homestead which they have to defend. It then has a trip through the wilderness looking for clues, dealing with horse thieves and invading goblin caves. All these things are good for 4e - encounters involving interesting terrain, a couple of skill challenges, and small encounter areas that suit 4e's skirmish approach to combat.
The later parts of the module I've extended a fair bit, folding in other bits and pieces (eg mixing elements of the Scepter Tower of Spellguard into the barrows from NDT, and using the Chamber of Eyes from Thunderspire Labyrinth as the main dungeon for the ruined city in NDT). So that's less a test of a conversion, although some individual encounters still got carried over and worked pretty well (like some of the tomb encounters).
Still, I'm pretty happy with how it's gone and certainly found the module a good help for getting my campaign going - NPCs, fighting with goblins, a mad wizard hunting down a tapestry, etc.